A number of interactive display devices have been developed to provide immediate visual feedback to a user of a computer, or other electronic or electromechanical equipment, and to thereby allow the user to precisely control operations related to the display. The movement of a cursor on a display, for example, permits the user to insert words within text as the user types a document. Similarly, by activating a slide bar at one side of the display, the user can scroll through the document much more rapidly. Pull-down and pop-up menus permit the user to activate other functions, such as saving or printing a document, checking the spelling of a document, etc. The display is interactive in the sense that signals from an input device, such as a keyboard, a mouse, touch-pad, touch-screen, or voice input system, is reflected in the modification of the display and in an underlying modification of data related to the display. That is, for example, not only is the cursor moved on the screen in response to input from the mouse, the underlying document, stored in electronic form within the computer, also reflects the cursor movement.
The real-time display provided by endoscopic instruments during surgery allows a surgeon to precisely control the position, direction, and speed of surgical tools in the process of delicate brain surgery that would otherwise be impossible. Although the tool might be positioned physically by powerful magnets, for example, control of the magnets and ultimately of the surgical tools, is in the hands of a surgeon. The surgeon may rely upon a display to provide him with immediate visual feedback via a live video feed while he employs a joystick or other input device to control the surgical tool. The surgeon may be operating by “dead reckoning” in that the only feedback he may be receiving is from the video feed and from some sort of an indicator which reveals the position of the tool within the patient, without revealing anything about the tool itself, that is, any changes in the cross-section of the tool, for example.
Interactive display devices are also used in the analysis of complex data sets. Insight may be gained by viewing the data in a unique manner that permits the visual correlation of data. Just as Linneaus' binomial organization of biological specimens into species and genus provided an organizational framework for understanding the vast diversity of the biosphere, an opportune display of data or of the results of operations performed on the data, may allow a user to gain insights that might otherwise be overlooked.
Although current interactive displays provide adequate feedback for many applications, there is a need for an interactive display which provides visual feedback to a user for operations that are more complex than simply positioning a cursor within a field of text. In particular, the display and on-screen measurement of time series data, such as electrocardiogram data, would be highly desirable.